Blue Mountains koalas are the most genetically diverse population recorded

September 14, 2018

We have exciting news about the importance of the Blue Mountains koala population for conservation of the species as a whole.

Science for Wildlife is a partner on a national-scale koala genomics study, with James Cook University, the University of Sydney and San Diego Zoo Global. We used cutting-edge genetic technology to answer critical questions about koala conservation across Australia. The results have just been published, and we found koalas in the Blue Mountains and Hawkesbury region have the highest level of genetic diversity in the country, out of 22 populations sampled from South Australia up to northern Queensland.

The paper states “The Blue Mountains (koala) population appears to hold much of the genetic diversity of the species… Subsequently, although it is important to preserve all populations of koalas, this region should be highlighted for future study if we are seeking to preserve existing diversity for the entire species”

These results are good news in the face of recent claims by WWF-Australia and the Nature Conservation Council that koalas will be extinct by 2050. Land clearing has terrible impacts on koalas and that needs to be addressed, but to conserve koalas in the long-term we also need to look more into these potentially large populations within our protected areas. These populations may well prevent extinction of the species.

Genetic diversity is also known as “fitness”; it is what allows a population of animals to adapt to evolutionary pressures over time, including things like disease outbreaks and changes in conditions. This genome study is the most comprehensive study to date and provides vital information at a species level and also on how koala populations are connected right across Australia. James Cook University Professor Kyall Zenger said the findings from the study were very exciting, given that koala numbers have been declining in many areas, and koalas are listed as a vulnerable species. The study has highlighted several key populations which appear to hold historic diversity from prior to European settlement and koala hunting for the fur trade in the early 20th Century.

“To effectively manage koalas across Australia and in captivity we must understand how genetically diverse these populations are – how ‘fit’ they are,” he said.

Shannon Kjeldsen, a PhD student working on the project at JCU, said her research also showed that two genetic “groups” appear to be present across Australia, but populations are still connected at a local scale.

“We know that it would be unwise to move koalas between these regions, because they live in different climates and have adapted to different environments, but this is the first study to give an indication of the geographic scale that these animals should be managed at,” Miss Kjeldsen said.

Dr Kellie Leigh from Science for Wildlife says this is an invaluable tool for prioritizing on-ground management of koalas. “With any threatened species, it’s important to conserve what is left of their genetic diversity to help secure their future. This information will help us do that. For example, now that we know how important the koalas are in the Blue Mountains and Hawkesbury region, we need to continue to find out more about their ecology and distribution so that we can conserve them.

It is an incredibly challenging area in which to study koalas, with very steep terrain and huge trees which make the koalas difficult to find and track. However, with this news and with the constant stream of surprises we are getting from studying koala ecology in the mountains, we know it’s well worth it.”

The Blue Mountains Koala Project includes sites across the Greater Blue Mountains World Heritage Area, including Wollemi, Blue Mountains and Kanangra-Boyd National Parks. It also runs onto the developed land that lies adjacent to the protected area, since koalas will move onto private land for good food trees.